Device for tensioning bundling straps



Feb. 2, 1965 /"f 5 mi-@wwwa D. P. SCHWESTER ETAL DEVICE FOR TENSIONING BUNDLING STRAPS Filed June 12, 1962 INVENTORS. //V/EL R SCH/VESTE'? www@ United States Patent O DEVICE FOR TENSIONING BUNDLING STRAPS Daniel P. Schwester, East Grange, and Francis A.

OLoughlin, Scotch Plains, NJ., assignors to The Thomas & Betts Co., Elizabeth, NJ., a corporation of New Jersey Filed June '12, 1962, Ser. No. 202,013 7 Claims. (Cl. Mtl-123.6)

The present application is an improvement over the structure disclosed in U.S. Patent No. 3,047,945, issued August 7, 1963.

The invention relates to devices for tensioning and locking tie straps or the like and more particularly to an improved hand tool adapted for tensioning a flexible plastic strap after it has been looped about a plurality of articles disposed in bunched parallelism, and for thereafter maintaining the strap under tension while the tool is manipulated to lock or otherwise secure the strap upon itself against reverse movement, the tool being subsequently actuated toward closed position to perform a severing operation on the extended free end portion of the strap.

More specifically, the invention resides in the herein described improvements in a hand tool of the parallel action pliers type, shown in the above Patent No. 3,047,945, which is particularly adapted for tensioning locking and severing individual exible plastic bundling straps of the character disclosed in U.S. Patent 3,002,557, whereby the application of such straps on a plurality of bunched insulated electric conductors, -for example, may be effected at spaced points therealong with greater convenience and dispatch and, with all tied straps under equal tension.

Heretofore, in tieing such bundling straps with the hand tool shown in the above Patent No. 3,047,945, it was necessary to bring the strap manipulating plate elements, on the jaws thereof, into a predetermined overlapping position, relative to the engaged body portion Iof the strap, solely by the operators skill or practice with the tool, and so hold the tool while turning it through an angle of 90 degrees to bring the engaged body portion of the strap into alignment with a pair of aligned slots extending centrally across the eyelet in the head-end portion thereof for the purpose of securing the strap against reverse movement after being drawn taut about a plurality of bunched electric conductors.

The aforesaid hand tool, however, possessed certain disadvantages in that the repeated movement of the jaw members toward each other to a Ipredetermined position required an unreasonable degree of skill since misjudgment resulted in the premature severance of such straps. Moreover, in the use of the aforesaid tool, the strap passed through the longitudinal center thereof and, in a modified form, pivotal action was such that one side of the jaw members was unobstructed for the sidewise insertion of a strap therebetween.

Accordingly, it is an object of the invention to provide improvements in a hand tool of the character described whereby the above noted disadvantages are obviated.

A further object of the invention is to provide a hand tool of the character described whereby it is possible for an inexperienced operator to tie a large number of bundling straps with greater efficiency and dispatch than was formerly possible with the unimproved hand tool in the hands 'of an experienced operator.

Another object of the invention is to provide an imice proved hand tool of the character described whereby any number of flexible plastic bundling straps are all placed under a uniform degree of tension in the tieing thereof with said tool.

A further object of the invention is to provide an improved hand tool of the forged steel type wherein the integral jaws thereof are olf-set at a small angle to the longitudinal center of the tool for the sidewise reception of a plastic bundling strap therebetween.

Another object 'of the invention is to provide an irnproved hand tool as described, wherein movement of the jaw members toward each other to a predetermined preset position is controlled automatically by means adapted to be released by an operator to effect a strap severing operation after the same has been secured against reverse movement.

With the above and other objects in view, the invention resides in the novel construction, combination, and arrangement of parts, the novel features of which are set forth with particularity in the appended claims, the invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, being best understood from the following description of a specic embodiment thereof, when taken in connection with the accompanying drawing in which:

FIGURE l is a perspective view illustrating the manner in which the improved hand tool is utilized in manipulating a plastic bundling strap into taut position about a plurality of bunched wire conductors and before severing the surplus end portion of the strap from its looped portion.

FIGURE 2 is a fragmentary side elevational view of the improved hand tool with its jaw members in full open position and showing a plastic bundling strap end portion as positioned sidewise therebetween.

FIGURE 3 is a fragmentary sectional View taken on the line 3-3 of FIGURE 2.

FIGURE 4 is a fragmentary side elevational view similar to FIGURE 3, showing the jaw members of the tool after they have been moved toward each other, short of cut-olf or closed position, with a free end portion of a bundling strap therebetween.

FIGURE 5 is a fragmentary sectional View taken on the line 5-5 of FIGURE 4.

FIGURE 6 is a view similar to FIGURE 5, showing the jaw members after they have been released for continued movement toward each other to cut-off position, from the position shown in FIGURE 4, Iby moving a detent member, hingedly connected to one jaw member, out of engagement with the other jaw member.

FIGURE 7 is a fragmentary cross-sectional View, taken on the line 7-7 of FIGURE 6.

FIGURE 8 is a fragmentary top plan view of the hand tool, shown in the preceding figures, illustrating the angularly off-set jaw members with respect to the longitudinal center line of the tool, and a portion of a bundling strap disposed between the jaw members at an angle to said longitudinal center line.

Referring to the drawing, the invention resides in a hand tool of the pliers type, generally indicated at 10, comprising a pair -of crossed handle members 12, of forged steel plivotally connected as at 14, in accordance with the Fivoted Tool Joint Construction disclosed in Porter Patent Number 2,920,927, said handle mem- .3 Y bers including a pair of jaws 16, of rectangular crosssection formed integral therewith and adapted to swing in lan are in scissors fashion when moved toward each other upon .angular manipulation of said handle members. As best shown in FIGURE 2, the jaws 16, and pivoted handle members 12, are yieldably maintained in open or spaced apart position by means of a coiled compression spring 18, disposed between the opposed inner faces of the h-andle members 12, adjacent the Vpivotalconnectionp14, with each of its opposite ends seated Iin a suitable recess formed in 'the inner faces of the respective handle members 14, by meansy of` a drill or the like, the hand grip portion of the handlemembers .12 being provided 'with a plastic coveringor sleeve 20, whereby 4to insulate-a portionfof, the tool 10 and at the same time lprovide a non-slip surface thereon. Y

In accordance with the invention and .as best shown in FIGURES 1 and 8, a major portion of the jaws 16,

`extending beyond thetfulcrum or-pivotal'connection 14, f between thefhandle members 12, is off-set or bent to the leftor toward the bottom edgeof the sheet, as `at 22, in FIGURE 8, and then in the-opposite direction,

4as .at 24,'to extend at a small angleV `toward the longit tudinal center line 26 through the handle members 12, whereby the jaws 16, are so off-set withV respect 'tosaid ,handle members that abundlingstrapS may be positioned between4 the jaws 16, .side-wise in angular off-set relation to the pivotal connection 14, as well as longitudinally of the jaws 16, from the nose-end thereof rearlwardly in spaced angular relation to the handle members.

Further in accordance with theinvention, the lower one of thejaws 16 terminatesat its nose-end. in an integral right4 angular extending lip or toothZS, in opposed relation to the nose-end of the opposite or upper jaw 16; the lip or tooth 25 being slightly tapered 4and its free end providedY with an angular rake or clearance to form a transverse knife edge28, havinga VV-notch 30 .centrally of its width topfovide` clearancefor` the ribbed,

vfaces of -the jaws-16, and in partial overlapping sliding contact relation with the lip or toothf25, when theV jaws 16 of the tool' 10 arev in the position shown in FIGURE 4.

As shown in FIGURES '2 and 3, the lextended free leg 38 of the angle plate 34 is providedwith a slot 40, extending inwardly from one side marginthereof for the snug recept-ion therein ofA the body Vportion'ofa bundling strapS, wherebythe widthof the slot 40 is slightly less than theA width of the'body portion of the strap S, for maintaining the same against lateral'as well as reverse movement when extended through thek slot.40.

Further inaccordance'with the'invention kand asbest shown in FIGURE l2,V means for drawing a strap S taut about a; plurality of bunched parallel linear'elernentsA E, in small successive increments Vof adjustment `comprises t an arcuate pawl 4 4, provided with Iapairof'spaced parallel earsY 46, ldepending fromV one end thereof and suitably apertured to serve as Ahinge members, Athe pawl being thereby pivotally mounted across the inner'fac'e of the lower jaw 16, as viewedin ,the drawing, adjacent its noseendby-meansfof a transverse'hinge pin -48 ex-V tending .through theears 46, and lower jaw 16, as shown in section in FIGURE 2, th-erpawl 44 being yieldably biased into upright position by means of a `spring 50V mounted on the hinge pin 48 with one of its ends bearing on the Aunderside of the pawl 44, and its opposite end bearing onthe bottom of a rectangular clearance recess or cavity 52, formed in' the innerf'ace of 'the lower upright position to a substantially horizontal position.

As shown in FIGURES 1, 2, 4 and 6, the convex side of the free end portion of lthe pawl 44 is suitably abraded, knurled, serrated or the like as at 54, whereby the pawl 44 is vadapted to bite or grip the linearly ribbed face of the body portion of the strap S, in response to repeated movement of the jaws 16 toward each other as when drawing -a bundling strap S taut.

.Further in vaccordance with theinvention and asbest shown in FIGURES 2, 4 yand 6, movement of the jaws 16 toward each other is limited by a -spring biased de- Vtent lever 56, pivotally Vmounted on theV straight rear portion of the upper jaw.16, by means of a suitable pivot pin 58. The detent lever 56 comprises a U-shaped end portion in cross-section, wherein one side terminates in a detent linger 60` depending beyond the inner'faee of the upper jaw 16 into closey proximity to the rear inner Yface 62 of the lower Vjaw 16, and a linger piece con- ;trol member 64 extending from its pivotedy end portion partly lover one ofv thehandle members 12. As shown -in FIGURE 2, the detent lever 56 is biased into operative position by meansl of a small coil spring 66 having V38 of the .angle plate 34.0nthe upper jaw 16,.whereby the said Aknifeedge 28 falls Vshortof movement Aacross the slot 40, and precludes a severing-operationon4 a bundling strap S until the free end or trigger. 64 of the detent lever56 is depressedr to free the jaws 16'for further movementtoward each otheras .exemplified in FIG- URE 6. f

In view of the foregoing, when considered in the' light of the accompanying-drawing, it will be clear, that the present invention provides.alforged solid frame hand tool of the pliers type wherein the jaws are dif-set or bent at an acute angle to the longitudinal centerV of said tool and t-o one side thereof asbest seen-inFIGURE 8, whereby theinser'tion of the tail-endofa ,bundling strap between the nose-endof the jaws, ,orbetween said jaws ,sidewise,rwill cause the strap to pass to onesidefof the fulcrum of the tool as it is ldrawn Ythrough the jaws. Moreover, the nose-endof one lof said jaws includes an angle plate suitably secured ythereto with its' free leg extending normal thereto and provided with an open ended transverseslot in one side edge, thereof for receiving and guiding astra-p between Tsaid jaws. `The nose-end of the other ofv said jaws includesvan integral, right angular extension terminating in atransverse knife edge having a V-notch centrallyfthereof for centering a Y strap thereonysaid cutting edge being-movable across said open ended slot in shearing relation in response to movement of said jaws towardY each other to sever said strap. VThe invention further provides a pivoted Vdetent means [on one Iof saidjaws for automaticallyV limiting movement `of said cutting edge shortof said open ended slot, Vto prevent severing `said strap while said tool is sol held and rotated through an angle of 90 degrees, said Y detentrneans being subsequently manually-released to t permit movement ,of said cutting edge to cut-offA position across said open ended slotV uponfu'rther movement of said jaws .toward each other. in response to further move- K ment of the handle members of saidv tool.

' While the inveniton hasbeen illustrated and described lwith respect to a preferredtembodiment thereof, it'is to be expressly understood that various changes and modifications may be made thereon without departing from the inventive concept underlying the same. Therefore, the invention is not to be limited except as is necessitated by the prior art and the scope of the appended claims.

What is claimed is:

1. A hand tool for tensioning and subsequently cutting a plastic strap when looped about a plurality of bunched articles comprising a pair of jaw members connected for movement toward and away from each other in response to movement of a pair of integral, spring influenced handle members, said jaw members being formed at an acute angle to the longitudinal center line of said tool and to one side of said center line, angular means provided on the nose-end of each of said jaw members disposed normal thereto in opposed relation adapted respectively for supporting and guiding an end portion of a plastic strap between said jaw members and for severing the end portion of said strap upon movement of said angular means to cut-olf position upon movement of said jaw members toward each other, and means pivotally mounted on `one of said jaw members including a detent normally engaging the other of said jaw members for limiting movement of said jaw members toward each other short of advancing said angular means to cut-off position, said last named means including a manually operable extension for releasing said detent to permit movement of said jaw members to cut-off position.

2. A hand tool for tensioning and subsequently cutting a plastic strap when looped about a plurality of bunched articles comprising a pair of jaw members connected for movement toward and away from each other in response to movement of a pair of integral, spring influenced handle members, said jaw members being formed at an acute angle to the longitudinal center line of said tool and to one side of said `center line, angular means provided on the nose-end of each of said jaw members disposed normal thereto in opposed relation adapted respectively for supporting and guiding an end portion of a plastic strap between said jaw members and for severing the end portion of said strap upon movement of said angular means to cut-off position upon movement of said jaw members toward each other, and means pivotally mounted on one of said jaw members including a detent normally engaging the other of said jaw members for limiting movement of said jaw members toward each other short of advancing said angular means to cut-oil? position, said last named means including a member extending partially over one of said handle members, manually operable for releasing said detent to permit movement of said jaw members to cut-off position.

3. The invention set forth in claim 2 characterized further in that said knife edge is provided centrally of its opposite ends with a V notch whereby to provide clearance for centering an end portion of a plastic strap thereon.

4. A hand tool for tensioning and subsequently cutting a plastic strap when looped about a plurality of bunched articles comprising a pair of jaw members pivotally connected for movement toward and away from each other in response to movement 0f a pair of integral, spring biased handle members, said jaw members being formed at an acute angle to the longitudinal center line of said tool and to one side thereof, a slotted means mounted on the nose-end of one of said jaw members normal thereto adapted for supporting and guiding an end portion of a strap through said jaw members, the nose-end of the other of said jaw members terminating in a right angular extension in opposed relation and provided with a transverse knife edge movable to cutoff position relative to said slotted means in response to movement `of said jaw members toward each other, and a spring biased detent means pivotally mounted on one of said jaw members normally engaging the other of said jaw members for limiting movement of said jaw members toward each other short of advancing said knife edge into shearing relation with said slotted means, said last named means including a manually operable extension for releasing said detent to permit movement of said knife edge to cut-o position.

5. A hand tool for tensioning and subsequently cutting a plastic strap when looped about a plurality of bunched articles comprising a pair of forged steel jaw members formed at an acute angle relative to the longitudinal center line of said tool and to one side of said center line adapted for movement toward each other in response to movement of a pair of spring influenced handle members normally in spaced apart position, an angle plate mounted on and across the nose-end of one of said jaw members having a transverse open-ended slot in one side edge thereof adapted to guide a tail-end portion of a plastic strap between said jaw members, a cutting member integral with and extending normal to the nose-end of the other of said jaw members movable to cut-oit position relative to said open-ended slot in response to movement of said jaw members toward each other, and a spring biased detent lever pivotally mounted on one of said jaw members and normally engaging the other of said jaw members to limit movement of said jaw members toward each other to advance said cutting member short of sa-id open-ended slot, said detent lever including a lever manually operable to release said detent from said one jaw member whereby said jaws are movable toward each other to advance said cutting member to cut-off position across said open-ended slot.

6. A hand tool for tensioning and subsequently cutting an end porti-on of a plastic strap when looped about a plurality of bunched articles comprising a pair of jaw members connected for movement toward and away from each other in response to movement of a pair of integral, spring biased handle members normally in spaced apart position, said jaw members being off-set at an acute angle to the longitudinal center line of said tool and to one side thereof, an angle plate having one leg thereof secured to one of said jaw members with its remaining leg extending across the nose-end thereof at right angles to the opposing faces of said jaw members, the extended leg of said angle plate being provided with a transverse, open ended slot in one side edge thereof adapted to support and guide an end portion of a looped strap between said jaw members, said other jaw member including an integral lip extending at right angles across the nose-end thereof in opposed relation to the extended leg of said angle plate, said integral lip being provided with a transverse knife edge 4on its free end movable across said open-ended slot in shearing relation therewith in response to movement of said jaw members toward each other, and a spring influenced detent lever pivotally mounted on one of said jaw members normally engaging the other of said jaw members to limit movement `of said integral lip short of the open-ended slot in the extended leg of said angle plate, said detent lever including a member extending partially over one of said handle members operable manually to release said detent to permit movement of said knife-edge to cut-off position relative to the open-ended slot in the extended free leg of said angle plate.

7. A hand tool for tensioning and subsequently cutting a plastic strap when looped about a plurality of bunched articles comprising a pair of jaw members formed at an acute angle relative to the longitudinal center line of said tool and disposed to one side of said center line adapted for movement toward each other in response to movement of a pair of integral, spring biased handle members normally in spaced apart position, an angle plate mounted across the nose-end of one of said jaw members having a transverse open-ended slot in one side edge of its extended free leg adapted to guide an end portion of a plastic strap between said jaw members, a spring biased serrated pawl pivotally mounted on the other of said jaw members across its inner face and if adjacent the nose-end thereof operable between said jaw members'upon movementthereof toward each other to impart small increments of relative .movement to said strap through said jaw `members, and a cutting member having a transverse knife edge integral with the noseend of-the other of said jaw members and extending nor- -mal thereto in opposedv relation to .the free leg of said angle .plate and movable across the open-ended slot therein in response to movementof said Vjaw members Y toward each other to sever a strap end portion, and a spring biased leverincluding a depending detent member Ypivotallymounted on one ofrsaid jaw members with its depending detent normally engaging the other .of said jaw members to limit movement of said cutting member short of said lopen-ended slot, said. lever includingy a 15 3,047,945

i member extending partially over .one of said handle membersfor manually releasing said kdetent member to permit movementof said cutting member and` said openended slot in the free leg of said angle plate to cut- Uo position, said cutting member having a V-notch centrally of itsknife-edge adapted for centering a strap end portion thereon.

t References Cited in the le'of this patent 

1. A HAND TOOL FOR TENSIONING AND SUBSEQUENTLY CUTTING A PLASTIC STAP WHEN LOOPED ABOUT A PLURALITY OF BUNCHED ARTICLES COMPRISING A PAIR OF JAW MEMBERS CONNECTED FOR MOVEMENT TOWARD AND AWAY FROM EACH OTHER IN RESPONSE TO MOVEMENT OF A PAIR OF INTEGRAL, SPRING INFLUENCED HANDLE MEMBERS, SAID JAW MEMBERS BEING FORMED AT AN ACUTE ANGLE TO THE LONGITUDINAL CENTER LINE OF SAID TOOL AND TO ONE SIDE OF SAID CENTER LINER, ANGULAR MEANS PROVIDED ON THE NOSE-END OF EACH OF SAID JAW MEMBERS DISPOSED NORMAL THERETO IN OPPOSED RELATION ADAPTED RESPECTIVELY FOR SUPPORTING AND GUIDING AN END PORTION OF A PLASTIC STRAP BETWEEN SAID JAW MEMBERS AND FOR SEVERING THE END PORTION OF SAID STRAP UPON MOVEMENT OF SAID ANGULAR MEANS TO CUT-OFF POSITION UPON MOVEMENT OF SAID JAW MEMBERS TOWARD EACH OTHER, AND MEANS PIVOTALLY MOUNTED ON ONE OF SAID JAW MEMBERS INCLUDING A DETENT NORMALLY ENGAGING THE OTHER OF SAID JAW MEMBERS FOR LIMITING MOVEMENT OF SAID JAW MEMBERS TOWARD EACH OTHER SHORT OF ADVANCING SAID ANGULAR MEANS TO CUT-OFF POSITION, SAID LAST NAMED MEANS INCLUDING A MANUALLY OPERABLE EXTENSION FOR RELEASING SAID DETENT TO PERMIT MOVEMENT OF SAID JAW MEMBERS TO CUT-OFF POSITION. 